Refrigeration device comprising a water tank

ABSTRACT

A refrigeration device having a water tank with at least one wall surface and a bottom surface and a flat heating system that is arranged on the water tank, wherein the flat heating system extends at least partially over the bottom surface.

The present invention relates to a refrigeration device comprising awater tank. Refrigeration devices such as refrigerators or freezerscomprising such a water tank, which supplies a tap attached to theoutside of the device with cooled drinking water, are enjoyingincreasing popularity with consumers.

The water in such a tank must never freeze, firstly because theexpansion of the water associated with the freezing process could damagethe tank and secondly because water cannot be tapped from a frozen tank.The water tank must therefore not have excessively close thermal contactwith an interior if this can be cooled down to temperatures below 0° C.

Refrigeration devices are known, whereby attempts are made to fulfillthis requirement, by the tank being embedded in a wall of therefrigeration device housing, so that it is surrounded by an insulatinglayer both outwardly and towards the interior. The ratio of the heatconductivities of these layers and the interior and ambient temperaturedetermine the temperature which the contents of the tank adopt understationary conditions. The problem nevertheless arises here in that theinterior temperature and, to an even greater degree than this, also theambient temperature are variable. A refrigeration device, which isdesigned for use in temperate zones, is not able to cool the tankcontents to a satisfying degree when used in tropical environments.Conversely, there is the risk with a refrigeration device which suppliescold water in tropical environments to a satisfying degree, that thetank contents will freeze in temperate zones, in particular when used inan unheated room. Such a conventional refrigeration device can thereforenot be manufactured uniformly for different climate zones. Themanufacture of models, which differ proportionately to the insulationlayer thickness on both sides of the water tank, requires an increasedmanufacturing outlay and also represents a significant restriction forthe user if the device can only be used in a restricted range of ambienttemperatures.

Furthermore, the need to insulate the water tank from the interior ofthe refrigeration device means that if fresh water flows out at ambienttemperature after tapping water from the tank, it takes a very long timeuntil this fresh water is cooled down.

The object of the present invention is to create a refrigeration device,which can be used in significantly variable ambient temperatures.

The object is achieved by a refrigeration device comprising a water tankhaving at least one side wall and a bottom surface, a flat heatingsystem arranged on the water tank for preventing the tank contents fromfreezing and extending at least partially upwards across the bottomsurface of the water tank, and in heat-conductive contact herewith. Bythe tank being thus heated from below, an efficient distribution of theheated water in the tank and thus an equal temperature distribution isensured, so that the freezing of the tank contents can be reliablyprevented. The bottom surface of the water tank is advantageously incomplete heat-conducting contact with the flat heating system.

If the water tank is embedded in a housing wall of the refrigerationdevice, the bottom surface is generally considerably smaller than theside wall as a result of the restricted thickness of the housing wall.To ensure adequate heating, the heating system expediently also extendsacross the side wall and is in heat-conducting contact herewith.

The side wall provided with the heating system is preferably facing anexterior of the housing, so that it is insulated against an interior ofthe refrigeration device and from the tank and its contents.

A second side wall of the tank preferably borders a hollow space, whichcommunicates with a cooled interior of the refrigeration device inorder, if necessary, to enable an efficient cooling of the contents ofthe water tank.

To fasten the heating system, the water tank can be advantageouslyprovided with clamping apparatuses. It is thus possible to dispense withgluing the heating system to the tank, since here, if it is notperformed sufficiently accurately, the risk of air bubbles between thewater tank and the heating system or wrinkling exists.

Close contact between a flexible heating system and the surface of thewater tank can be ensured in a simple fashion if the surface of thewater tank between two clamping projections is convex.

Further features and advantages of the invention result from thesubsequent description of exemplary embodiments with reference to theappended figures, in which;

FIG. 1 shows a schematic cutout through an inventive refrigerationdevice comprising a water tank mounted in a niche of the door,

FIG. 2 shows a perspective view of the water tank,

FIG. 3 shows a detailed cutout of the water tank, and

FIG. 4 shows a second detailed cutout in accordance with a furtherdeveloped embodiment.

FIG. 1 shows a schematic cutout through a refrigeration devicecomprising a water tank according to the present invention. Therefrigeration device shown can be a freezer or the freezer part of aside-by-side combination device. The walls of the carcass 1 and door 2,which surround the interior 3 of the device, are realized in a mannerknown per se in each instance with a solid outer skin and inner skinwhich enclose the intermediate space foamed with insulating resin. Theinner skin 4 of the door 2 is deep drawn in one piece from plastic andhas a protrusion 5 protruding into the interior 3 in a central region.The outer skin is composed of an essentially flat front panel 6, whichis shown here covered with a furniture plate 7, and is cut into acentral window, and with an essentially square housing 8 which opensforwards and is injection molded from plastic, said housing 8 engagingin the protrusion 5 of the inner skin 4 and filling the window of thefront panel 6. Two levels 9 on the bottom and top wall of the housing 8arrange the niche formed in its interior into an inner region 10 and anouter region 11 which opens toward the front side of the device. Theinner region 10 is essentially closed by a panel 12 which is insertedinto the housing 8 from the front and rests against the level 9. A watertank 13 is accommodated in the inner region 10. Pipes 14 and/or 15connect the water tank 13 to the drinking water network on the one handand to a tap 16 on the other hand in the outer region 11 of the housing8.

A hollow space 17 is located between a rear of the approximately squarewater tank 13 and a rear wall of the housing 8. Several passages 18, ofwhich only one can be seen in the cutout in FIG. 1, connect the hollowspace 17 to the interior 3. A control element (not shown in FIG. 1),like for instance a flap or a fan, is arranged on at least one of thesepassages 18, said control element enabling the circulation of airbetween the hollow space 17 and the interior 3 to be restricted to aminimum if the water temperature notified by a sensor attached the tank13 is low enough and/or allows or drives air circulation, if after theinflow of fresh water into the tank 13, the water temperature in thetank 13 is above the desired value.

An automatic ice maker 19 and a storage container 20, in which theicemaker 19 outputs frozen ice cubes, is located in the interior 3. Anoutput opening of the storage container 20 is above a shaft 21, whichextends through the wall of the door 2, and opens into the housing 8 onthe ceiling of the outer region 11. A container placed in the outerregion 11 can be filled both with cold water from the tank 13 and alsowith ice cubes from the storage container 20.

FIG. 2 shows a perspective view of the water tank 13, seen from itsfront side facing the niche 11. The water tank 13 is essentially squareby design. It is essentially composed of a flat shell 22, which forms afront wall 23, a bottom surface 24, a ceiling 25 and side walls 26 ofthe tank 13, and a rear wall 28, which is welded to a collar 27 of theshell 22 which runs around the bottom surface 24, ceiling 25 and sidewalls 26. Inlet and outlet connections 29, 30 protrude from the upperedge of the front wall 23. A bag 31 made of plastic foil is welded toone of the side walls 26 adjacent to the outlet connection 30, said bagbeing provided to accommodate a temperature sensor inserted from abovein order to detect the water temperature in the tank 1.

The tank 13 is sealed by a flat welding, designated in FIG. 4 by 39,between the collar 27 and the rear wall 28.

Two brackets 32 are molded on the front wall 23, said brackets holding afoil heating system 33 against the wall 23 using pressure. The foilheating system extends across the larger part of the front wall 23 andthe bottom surface 24 until reaching the vicinity of the collar 27,where it is held by further brackets (not shown in this view). By thefoil heating system 33 extending beyond the lower edge of the wall 23which protrudes across an imaginary connecting plane between the upperand lower brackets, it is held in close contact with the shell 22 overits entire surface.

To be able to comfortably insert the foil heating system 33 into thebrackets 32 and hold the same continuously, an upper and a lower edge ofthe foil heating system 33, as shown by way of example in FIG. 3 withthe aid of a cutout through the upper edge region of the foil heatingsystem 33, is wrapped around a rigid rod-type beading 34. This beading34 provides the otherwise flexible foil heating system 33 with thenecessary rigidity in order to be inserted into the bracket 32 andprovides for a continuous hold by means of a form-fit connection. Thebracket 32 which is elastically braced by the beading 34 from the wall23 simultaneously exerts an upwardly directed traction on the foilheating system 33, so that this is held under tension and rests closelyagainst the surface of the tank 13.

The anchorage of the lower edge of the foil heating system 33 to thebottom surface 24 can take place with the aid of brackets which aresimilar to the brackets 32. FIG. 4 shows a type of anchorage which ismodified in this respect. The edge of the foil heating system 33 is alsowrapped around a rod-type beading 34 here. The circumferential collar 27of the shell 22 is lengthened outwards by an angled web 36 in eachinstance so that a groove 35 results on the front of the collar 27,which receives the beading 34. The rear wall 28 is provided with acircumferential web 37, which supports a projection 38 protruding fromeach side of the web 36 and partially closes the groove 35. The web 37and projection 38 function together as a bracket, which holds thebeading 34 and thereto the lower edge of the foil heating system 33 inthe groove 35.

It is conceivable to anchor an upper edge of the foil heating system inan arrangement which is mirror-symmetrical relative to therepresentation in Fig. between the ceiling 25 and the rear wall 28 ofthe tank 13. In this case, the section of the foil heating system whichextends across the ceiling 25 is expediently free of heat conductors,since heat released on the bottom surface 24 and the front wall 23transmits significantly more efficiently to the contents of the tank 13.

1-8. (canceled)
 9. A refrigeration device, comprising: a water tank withat least one wall surface and a bottom surface; and a flat heatingsystem arranged on the water tank, wherein the flat heating systemextends at least partially over the bottom surface.
 10. Therefrigeration device of claim 9, wherein the flat heating systemcompletely covers the bottom surface.
 11. The refrigeration device ofclaim 9, wherein the water tank is embedded in a housing wall of therefrigeration device, and wherein the flat heating system extends overthe wall surface.
 12. The refrigeration device of claim 11, furthercomprising a housing, wherein the wall surface of the water tank facesan exterior of the housing.
 13. The refrigeration device of claim 11,wherein a hollow space borders a second wall surface of the water tank,the hollow space communicating with a cooled interior of therefrigeration device.
 14. The refrigeration device of claim 13, whereinthe hollow space is an air duct into which cold air that is forciblycirculated in the interior flows.
 15. The refrigeration device of claim9, wherein the water tank supports clamping projections to which theflat heating system is fastened.
 16. The refrigeration device of claim12, wherein the flat heating system is flexible, and wherein an area ofthe water tank is convex between two of the clamping projections.